Reference is to Improper Blessing
The word ברך in the piel, when God is the object, typically means to actively "praise God" for something, and in the pual, to refer passively to "God being praised" for something.
I do not think there is reason to have that meaning changed in these instances, nor to conjecture that it is a euphemism, as many have.1
Rather, contexts indicates a particular intention. What these instances indicate is that one can praise God for something they should not be praising Him for; i.e., improper praise of God is equivalent to "cursing" or despising God, because one is improperly commenting on the character of God through a misapplied blessing. So the choice to translate ברך as "curse" is to reflect that the blessing is in fact not being to God's glory, to His praise.
When one blesses sinfulness, and then attributes that sin as being God's blessing, one actually malign's God and His ways. Such is the idea of the Psa 10:3 usage (NKJV):
For the wicked boasts of his heart’s desire;
He blesses the greedy and renounces the LORD.
The wicked blesses that which is wrong to bless, attributing it to YHWH, but in doing so, truly renouncing YHWH's ways.
Note how in 1 Kg 21:10 and 13 the set up for the accusation against Naboth was to first "seat Naboth with high honor among the people." This exaltation by others would then make the false witness believable that Naboth might have blessed God and the king inappropriately with respect to Naboth's own current exaltation, i.e., a prideful boast perhaps, such as "I praise God and king for their overdue recognition of my great worth... blah, blah." Whatever the exact charge, we are not told. But the point, I believe, is that Naboth is being charged with praising God and king for something they ought not be praised for, thus maligning the character of both.
The usages in Job are linked to circumstances as well; circumstances in which one may not be in the right state of mind, and thus improperly bless God for that which one should not.
One time when this wrong state of mind is likely to occur is when one is celebrating, especially if alcohol is included (but not necessarily so). In Job 1:5, we find that it was after Job's children's times of feasting that he would offer intercessory sacrifice for them, as during that time they might have "sinned" and offered a misplaced blessing to God for that sin. Not to be too graphic here in illustrating, but how many people have attended parties, got drunk, done things they should not have with one another, and in their hearts thanked God for the "good time" they had, when that "good time" was filled with sin? That, I believe, is the image Job 1:5 is intended to evoke, causing Job to feel the need to sanctify his children again to God, giving sacrifice to cover any sin they may have done, and done thinking it was God's blessing to them.
In like manner, but a distinctly different situation, in Job 1:11 and 2:5 Satan is saying that the calamity God allows in Job's life will bring about circumstances in which Job will praise God "to his face" for things Job should not praise God for.
Perhaps Satan believes Job will sarcastically react: "Thanks, God, for wiping out my possessions and my children, and thanks, God, for such wonderful health you have granted me with these boils...." This seems to be the essence of what Job's wife is encouraging him to do in 2:9.
Or, if not sarcastically, improperly otherwise, like Job praising God for the judgment brought upon him, though he was righteous in God's eyes (so Job 1:1), and thus praising God for apparently judging righteousness, which reflects poorly on God's character. This seems to be precisely in part the error Job's friends make—they did not speak right about God's ways (42:7), failing to recognize that Job was righteous and not deserving of such things based upon anything Job had specifically done.
How did Job really respond? Not as Satan intended. After the first incident, we learn Job "blessed" God's name (1:21) and "did not sin nor charge God with wrong" (1:22), and after the second, that "In all this Job did not sin with his lips" (2:10).
Job had some character flaws revealed through the incidents (e.g. Job 42:1-6), but his actions toward God and fellow man were never in question prior to Job's testing. This testing was what the calamities came for; to prove Job faithful, including not to praise God for that which He should not be praised.
The word ברך, though translated "curse" to indicate the "praise" is not true to glorifying God, does not really need to be remapped to a meaning opposite what it always has. Mis-given praise to God is not a blessing to God, it is blasphemy, a curse to His name, His character. This appears to be the idea in all the contexts in which it arises that it is translated as "curse."2
1 The only reason to conjecture such is a misplaced notion of thinking God cannot be associated with cursing. But Exo 22:28, Lev 24:15, Isa 8:21 all use קלל ("curse") in conjunction with God, so the use of it was established before the writing of 1 Kings and Psalm 10:3. One would have to argue that these writers, along with the author of Job, specifically felt compelled to not associate a person cursing God, when Moses had.
2 So rather than "a blessing overdone and so really a curse," the context appears to indicate "a blessing mis-attributed and so really a curse" to the one it is mis-attributed toward.